Snellville is a city in Gwinnett County, Georgia, United States, east of Atlanta. Its population was 20,573 at the 2020 census. It is a develop…Snellville is a city in Gwinnett County, Georgia, United States, east of Atlanta. Its population was 20,573 at the 2020 census. It is a developed suburb of Atlanta and a part of the Atlanta metropolitan area, and is located roughly 33 miles east of downtown Atlanta via US 78 and Interstate 285.